1 /* 2 * CAM request queue management definitions. 3 * 4 * Copyright (c) 1997 Justin T. Gibbs. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions, and the following disclaimer, 12 * without modification, immediately at the beginning of the file. 13 * 2. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR 20 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * $FreeBSD: src/sys/cam/cam_queue.h,v 1.6 1999/12/29 04:54:26 peter Exp $ 29 * $DragonFly: src/sys/bus/cam/cam_queue.h,v 1.3 2004/03/15 01:10:30 dillon Exp $ 30 */ 31 32 #ifndef _CAM_CAM_QUEUE_H 33 #define _CAM_CAM_QUEUE_H 1 34 35 #ifdef _KERNEL 36 37 #include <sys/queue.h> 38 39 /* 40 * This structure implements a heap based priority queue. The queue 41 * assumes that the objects stored in it begin with a cam_qentry 42 * structure holding the priority information used to sort the objects. 43 * This structure is opaque to clients (outside of the XPT layer) to allow 44 * the implementation to change without affecting them. 45 */ 46 struct camq { 47 cam_pinfo **queue_array; 48 int array_size; 49 int entries; 50 u_int32_t generation; 51 u_int32_t qfrozen_cnt; 52 }; 53 54 TAILQ_HEAD(ccb_hdr_tailq, ccb_hdr); 55 LIST_HEAD(ccb_hdr_list, ccb_hdr); 56 SLIST_HEAD(ccb_hdr_slist, ccb_hdr); 57 58 struct cam_ccbq { 59 struct camq queue; 60 int devq_openings; 61 int dev_openings; 62 int dev_active; 63 int held; 64 struct ccb_hdr_tailq active_ccbs; 65 }; 66 67 struct cam_ed; 68 69 struct cam_devq { 70 struct camq alloc_queue; 71 struct camq send_queue; 72 struct cam_ed *active_dev; 73 int alloc_openings; 74 int alloc_active; 75 int send_openings; 76 int send_active; 77 int refcount; 78 int max_openings; 79 }; 80 81 82 struct cam_devq *cam_devq_alloc(int devices, int openings); 83 84 int cam_devq_init(struct cam_devq *devq, int devices, 85 int openings); 86 void cam_devq_reference(struct cam_devq *devq); 87 void cam_devq_release(struct cam_devq *devq); 88 u_int32_t cam_devq_resize(struct cam_devq *camq, int openings); 89 void cam_devq_set_openings(struct cam_devq *devq, int openings); 90 91 92 /* 93 * Allocate a cam_ccb_queue structure and initialize it. 94 */ 95 struct cam_ccbq *cam_ccbq_alloc(int openings); 96 97 u_int32_t cam_ccbq_resize(struct cam_ccbq *ccbq, int devices); 98 99 int cam_ccbq_init(struct cam_ccbq *ccbq, int openings); 100 101 void cam_ccbq_free(struct cam_ccbq *ccbq); 102 103 void cam_ccbq_fini(struct cam_ccbq *ccbq); 104 105 /* 106 * Allocate and initialize a cam_queue structure. 107 */ 108 struct camq *camq_alloc(int size); 109 110 /* 111 * Resize a cam queue 112 */ 113 u_int32_t camq_resize(struct camq *queue, int new_size); 114 115 /* 116 * Initialize a camq structure. Return 0 on success, 1 on failure. 117 */ 118 int camq_init(struct camq *camq, int size); 119 120 /* 121 * Free a cam_queue structure. This should only be called if a controller 122 * driver failes somehow during its attach routine or is unloaded and has 123 * obtained a cam_queue structure. 124 */ 125 void camq_free(struct camq *queue); 126 127 /* 128 * Finialize any internal storage or state of a cam_queue. 129 */ 130 void camq_fini(struct camq *queue); 131 132 /* 133 * cam_queue_insert: Given a CAM queue with at least one open spot, 134 * insert the new entry maintaining order. 135 */ 136 void camq_insert(struct camq *queue, cam_pinfo *new_entry); 137 138 /* 139 * camq_remove: Remove and arbitrary entry from the queue maintaining 140 * queue order. 141 */ 142 cam_pinfo *camq_remove(struct camq *queue, int index); 143 #define CAMQ_HEAD 1 /* Head of queue index */ 144 145 /* Index the first element in the heap */ 146 #define CAMQ_GET_HEAD(camq) ((camq)->queue_array[CAMQ_HEAD]) 147 148 /* 149 * camq_change_priority: Raise or lower the priority of an entry 150 * maintaining queue order. 151 */ 152 void camq_change_priority(struct camq *queue, int index, 153 u_int32_t new_priority); 154 155 static __inline int 156 cam_ccbq_pending_ccb_count(struct cam_ccbq *ccbq); 157 158 static __inline void 159 cam_ccbq_take_opening(struct cam_ccbq *ccbq); 160 161 static __inline void 162 cam_ccbq_insert_ccb(struct cam_ccbq *ccbq, union ccb *new_ccb); 163 164 static __inline void 165 cam_ccbq_remove_ccb(struct cam_ccbq *ccbq, union ccb *ccb); 166 167 static __inline union ccb * 168 cam_ccbq_peek_ccb(struct cam_ccbq *ccbq, int index); 169 170 static __inline void 171 cam_ccbq_send_ccb(struct cam_ccbq *queue, union ccb *send_ccb); 172 173 static __inline void 174 cam_ccbq_ccb_done(struct cam_ccbq *ccbq, union ccb *done_ccb); 175 176 static __inline void 177 cam_ccbq_release_opening(struct cam_ccbq *ccbq); 178 179 180 static __inline int 181 cam_ccbq_pending_ccb_count(struct cam_ccbq *ccbq) 182 { 183 return (ccbq->queue.entries); 184 } 185 186 static __inline void 187 cam_ccbq_take_opening(struct cam_ccbq *ccbq) 188 { 189 ccbq->devq_openings--; 190 ccbq->held++; 191 } 192 193 static __inline void 194 cam_ccbq_insert_ccb(struct cam_ccbq *ccbq, union ccb *new_ccb) 195 { 196 ccbq->held--; 197 camq_insert(&ccbq->queue, &new_ccb->ccb_h.pinfo); 198 } 199 200 static __inline void 201 cam_ccbq_remove_ccb(struct cam_ccbq *ccbq, union ccb *ccb) 202 { 203 camq_remove(&ccbq->queue, ccb->ccb_h.pinfo.index); 204 } 205 206 static __inline union ccb * 207 cam_ccbq_peek_ccb(struct cam_ccbq *ccbq, int index) 208 { 209 return((union ccb *)ccbq->queue.queue_array[index]); 210 } 211 212 static __inline void 213 cam_ccbq_send_ccb(struct cam_ccbq *ccbq, union ccb *send_ccb) 214 { 215 216 TAILQ_INSERT_TAIL(&ccbq->active_ccbs, 217 &(send_ccb->ccb_h), 218 xpt_links.tqe); 219 send_ccb->ccb_h.pinfo.index = CAM_ACTIVE_INDEX; 220 ccbq->dev_active++; 221 ccbq->dev_openings--; 222 } 223 224 static __inline void 225 cam_ccbq_ccb_done(struct cam_ccbq *ccbq, union ccb *done_ccb) 226 { 227 TAILQ_REMOVE(&ccbq->active_ccbs, &done_ccb->ccb_h, 228 xpt_links.tqe); 229 ccbq->dev_active--; 230 ccbq->dev_openings++; 231 ccbq->held++; 232 } 233 234 static __inline void 235 cam_ccbq_release_opening(struct cam_ccbq *ccbq) 236 { 237 ccbq->held--; 238 ccbq->devq_openings++; 239 } 240 241 #endif /* _KERNEL */ 242 #endif /* _CAM_CAM_QUEUE_H */ 243